Electric discharge device and electrode assembly therefor



Aug. 12, 1947. 2,425,593

ELECTRIC DISCHARGE DEVICE AND ELECTRODE ASSEMBLY THEREFOR W. S. BRIAN Filed June 15, 1945 Inventor: William 5. Brian,

His Attorney.

Patented Aug. 12, 1947 ELECTRIC DISCHARGE DEVICE AND ELEC- TRODE ASSEDIBLY THEREFOR William S. Brian, Owensboro, Ky assignor to General Electric Company, a corporation of New York Application 1m 15, 1945,'seria1 No. 599,712

15 Claims. (01.2.50-275) My invention relates to improved electric discharge devices and particularly to an improved unitary electrode assembly and mounting therefor. The invention is in the nature of an improvement on the discharge devices described and claimed in my copending patent application Serial No. 557,126, filed October 4, 1944, and assigned to the assignee of the present invention.

It is an object of my invention to provide a new and improved unitary electrode assembly adapted to be manufactured with a minimum of hand labor. v

It is another object of my invention to provide a new and improved unitary electrode assembly which is rugged and not readily damaged during assembly or while it is carried in inventory as a component part. I

It is still another object of my invention to provide a new and improved mounting for a unitary electrode assembly,

It is a still further object of my invention to provide an improved electric discharge device in which a high degree of accuracy in the spacing of electrode is insured while at the same time the labor required for assembly isreduced. v

My invention will be better understood by reference to the following description, taken in connection with the accompanying drawing, and its scope will be pointed out in the appended claims. In the drawing, Fig. 1 is an elevational View, partly in section, of an electric discharge device embodying my invention; Fig. 2 is a sectional view taken along the line 2-2 of Fig. "1; Fig. 2a is a perspective view of the electrode assembly support of the device of Figs. 1 and 2; Fig. 3 is an elevational view, in section, of the unitary electrode assembly employed in the device of Figs. 1 and 2; and Figs. 4 and 5 are detail views showing a modified cathode structure.

Referring now to the drawing, the device includes a circular metal header I having a plurality of openings arranged about a central positioning hub 2 for the reception of rigid lead-in conductors 3, each of which is sealed to the header by a body of glass 4. The lead-in conductors 3 are connected at their upper ends with the various electrodes of a unitary electrode assemblydesignated generally bythe numeral 5. As illustrated clearly in Fig. 3, the electrode assembly includes an open-ended generally cylindrical or cupshaped retaining member 6 having an end wall I joined to side wall portions 8 and 9 which terminate at their, upper ends in flanges 10. The electrode assembly includes a plurality of spacer members H-IS, inclusive, which are preferably annular in shape and formed of suitable insulating material such as steatite or an aluminasilica-magnesia compound of the type commercially known as Alsamig. The spacers are preferably accurately ground or lapped to the desired thickness to accurately determine the relative spacing of the various electrodes. As indicated in the drawing, an anode having a planar central portion I 6 is provided with a marginal portion l1 received between spacers H and 12. An in directly heated wafer-like thermionic cathode is provided by a pair of sheet metal members l8 and 19 which are joined together to form a cylindrical enclosure within which a heater element, including lead-in wires 20 and 2|, is positioned. As indicated clearly in 2, the cathode is pro-- vided with outwardly extending tabs 22 which are received between the spacers l2 and I3. The

spacers I2 and I3 differ from the remaining spacers in that they each include an inwardly extending flange 23 which substantially closes off the area around the cathode. These members are also provided with a recess 24 to receive the'current supply conductors '20 and 2| of the cathode heater. As will be readily appreciated by those skilled in the art, the opposite exterior surfaces of the cathode are preferably coated 'with an electron emission enhancing material such as a compound containing one or more of the alkaline earth oxides. A control member or grid having a central portion of wire or, mesh 25 is provided with an outwardly extending marginal flange 26 whichis received between the spacers l3 and 14. A second anode or plate electrode 21 0f the same construction as the anode I6 is provided with a marginal portion 28 which is received between the spacers l4 and I5 As illustrated in the drawing, the side walls of the member 6 are preferably substantially the full height of the stack including the electrodes and spacers so that there is provided a suitable retainer into which the parts may be dispensed at the different stations of an automatic machine. When the electrodes and spacers are in position with the lower spacer resting on the end wall of the member 6 the unitary assembly is completed by a retaining cap 29 having a central wall portion 30 engaging the uppfi r spacer l5 and an outwardly extending flange 3| whichis welded or otherwise bonded to the flange ID of the retainer 6. The dimensions of the various parts are preferably chosen so that after positioning of the parts and prior to the bonding operation, the flanges are slightly separated. In this manner, the bonding operation is effective to apply presthem from lateral movement.

ductors 53 and 54 of the heater element.

.terial.

2,425,593 i "I 7 Y 10 during operation and firmly retains the electrodes. I

and spacers in assembled relation. The wall pore tions'8 and 9 of the cup-like retaining member 6 are provided with extensions shownin Fig. 1'

and designated by numerals 34 and 35 which are free of the retainer at both ends so that they may resiliently engage the spacers and restrain As clearly shown in Fig. 2, these extensions are curved inwardly toward the spacers. The unitary assembly 5 is supported from a flange 36 on the header I by a .sheet metal support including a circular flange v3'! which registers with the flange 35 and a pair of diametrically opposed vertical supports 38 and 39 :which terminate at their upper ends in inwardly directed flanges 40 and M, respectively. Theflanges 4!! and 4| are bonded, as by welding,

.to the flanges of the retaining members of the electrode assembly. I As illustrated in Figs. 1' and 2, a suitable getter strip 4'! .may be connected between one of the lead-inconductors 3 and the arm 38 of the sheet metal support. The envelope of the discharge device includes a sheet metal can-like member 48 having an outwardly extend ing flange surrounding the open end thereof and registering with the flanges 3S and 31. The unitary electrode assembly and mounting described-above provide a support which is entirely independent of the lead-in conductors.

. Inassembling the discharge device described above, the unitary electrode assembly is welded to the support including the arms 38 and 39. The support is then positioned on the header with flange 31' of the support registering with flange 36. The connections between the various electrodes and the lead-in conductorsare then made and the assembly completed by placing the envelope 48 in position with the flange 49 registering with the flange 31. The three flanges are preferably welded together in one operation. Thetube may be exhausted before the welding 3B and 49 or, if desired, exhaust of the device may be accomplished through a suitable tubulation (not shown) In some applications it is desirable to operate, the cathodes of the different discharge paths of a duplex discharge device at different voltages. In such a case it will be apparent that two independent cathode structures may be supported in spaced and insulated relation in the assembly. In Figs. 4 and 5 I have illustrated amodified cathode structure in which two mutually insulated cathode spacers are heated by a single heater element Referring to the drawing, a heater element including a coil of insulated wire 50 is supported in an insulating spacer 5| having a suitable recess 52 for receiving the terminal con- Posi-v tioned on opposite sides of the spacer 5! are cathode disks 55 and 5B which are preferably.

coated with an electron emission enhancing ma- 7 Each of these disks is provided with a plurality of supporting portions in the form of wires 51, 58 and 59 which are bonded to the disks and extend radially therefrom; As illils trated in Fig. 4, these supports arereceived 7 suitable recesses Ell formed in the spacer 5|. The Wires 59 are preferably longer than the supporting wires 51 and 58 and provide suitable terminals for connecting the cathode members with the lead-in conductors of the device. The spacer 5| is provided with a plurality of openings 6| in the region surrounding the cathode disks 55 and v 56 to minimize the transfer of heat from the oath-f .ode to the supporting tructure. 7

In Fig. 5, the spacer 5| and cathode elements assembly shownin Fig. .5 occupies 'generally the space occupied by the cathode l8i9 and space elements l2 and I3 as shown in Fig. 3.

It is apparent from the foregoing description of the illustrated embodiment of .my invention that a very simple and rugged unitary electrode assembly is provided which is particularly well adapted for manufacture on automatic machinery. The insulating spacers and electrodes I may be alternately dispensed into the retaining member 6 and the assembly completed by welding the flange of the cover member and the flange of the retainer 6. This construction avoids'the time consuming assembly step of threading the support wires through the insulating spacers which is present in the manufacture of practicale ly all conventional receiving type tubes; The.

invention provides a structure which makes possible this saving of labor and at the sametime results in a more compact and accurately constructed device so that the tube characteristics are more uniform and more readily reproduced. The support of this assembly is also simple and rugged while at the same time providing ready access to the lead-in conductors for making the connections between the lead-in conductors and the various electrodes.

'While I have shown and described a particular embodiment of my invention, it will be obvious to those skilled in the art that changes and modifications may be made without departing from my invention in its broader aspects, and I, therefore, aim in the appended claims to cover all such changes and modifications as fall within the.

true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is: V V 1 1. An electrode assembly comprising. a plurality of electrodes having generally planar active surfaces and marginal supporting portions, a plurality of spacers assembled in astack with said marginal portions received between the various spacers to support said electrodes in mutually spaced and insulated relation, and a pair of metal retaining members positioned in engagement with the opposite ends of said stack, said retaining members having portions bonded together to form a unitary structure for holding said electrodes and spacers in assembled relation.

2. An electrode assembly comprising a plurality of electrodes including marginal supporting portions, a plurality of spacers assembled in a stack with said marginal portions received be- In order to prevent trodes in mutually spaced and insulated relation, a cup-like metal structure adapted to receive and retain said stack of spacers and electrodes, and a retaining member .engaging said stack at the end thereof adjacent the open end of said cup and joined to said cup-like structure to form a unitary electrode assembly.

3. An electrode assembly comprising a plurality of electrodes having generally planar active surfaces and marginal supporting portions, a plurality of spacer rings assembled in a stack with said marginal portions received. between the various rings to support said electrodes in mutually spaced and insulated relation, a metal ember having an end Wal ands Wal pertions substantially equal in height to the height of said stack, said stack bein received in said member with one end thereof in engagement with said end wall, and a second metal member having a wall portion engaging the opposite end of said stack and a second portion bonded to said first metal member.

4. An electrode assembly comprising a plurality of electrodes having generally planar active surfaces and marginal supporting portions, a plurality of ring-like spacers of insulating material assembled in a stack with said marginal portions received between the various spacers to support said electrodes in mutually spaced and insulated relation, and a pair of metal retaining members positioned in engagement with the opposite ends of said stack, at least one of said retaining members having portions extending axially of said stack and mechanically connected to the other of said members to provide a unitary electrode assembly.

5. An electrode assembly comprising a plurality of electrodes having generally planar active surfaces and marginal supporting portions, a plurality of spacers assembled in a stack with said marginal portions received between the various spacers to support said electrodes in mutually spaced and insulated relation, a cup-like retaining structure engaging one end of said stack and including side Wall portions extending axially along the outside of said stack and a retaining member engaging the other end of said stack, and means mechanically connecting said side wall portions to said retaining member.

6. An electrode assembly comprising a plurality of electrodes having central active portions and marginal supporting portions, a plurality of spacers of insulating material assembled in a stack with said marginal portions received between the various spacers to support said electrodes in mutually spaced and insulated relation and a pair of retaining members positioned in engagement with the opposite ends of said stack, means extending axially of and on the exterior of said stack and mechanically connecting said members together to provide a unitary electrode assembly, and at least one resilient section in the retaining structure provided by said last mentioned means and said pair of metal members.

7. An electrode assembly comprising a plurality of electrodes having generally planar active surfaces and marginal supporting portions, a plurality of ring-like spacers of insulating material assembled in a stack with said marginal portions received between the various spacers to support said electrodes in mutually spaced and insulated relation, and a pair of metal retainin members positioned in engagement with the opposite ends of said stack, at least one of said members having portions extending axially of said stack and mechamcallyconnected to the other of said members to provide a it e e trode a sembly and a resilient section formed in at least one oi said membe s, Said members being dr wn into en agement with t e oppos t nds o sai teels when said member ar connected to her t flex said resilient sections.

8- Anv el c di arge d vi in l din a header having an outwardly extending flange, a unitary electrode assembly including a retainin struct e and a u a it o ede emen and spacer rings mounted withinsaid retaining structure, and a support for said electrode as:- sembly includin a flange resting on the flange of said header and upwardly extending portions joined to opposite sides of said retaining structure.

9. An electric discharge device including a header, a unitary electrode assembly including a metallic retaining structure and a plurality of electrode elements and spacer rings mounted within said metallic retaining structure, and a support for said electrode assembly including a portion resting on said header and upwardly extending portions joined to opposite sides of said retaining structure.

10. An electric discharge device comprising an envelope including a header, a plurality of leadin conductors sealed through said header, a unitary electrode assembly including a retaining structure and a plurality of electrode elements and spacer rings mounted within said retaining structure, flexible connections between said leadin conductors and the various electrodes, and a support for said electrode assembly including a portion resting on said header and upwardly ex tending portions engaging said retaining structure to support said assembly independently of said lead-in conductors.

11. An electric discharge device including a circular header having a plurality of lead-in conductors extending through said header and arranged in a circle, a unitary electrode assembly including a retaining structure and a plurality of planar electrode elements and spacer rings mounted within said retaining structure, and a support for said electrode assembly resting on said header outside of said circle and having upwardly extending portions joined to said retaining structure, said support and said retaining structure having openings in the side walls thereof to facilitate the making of connections between the lead-in conductors and the various electrodes of the assembly.

12. An electric discharge device including a header, a unitary electrode assembly including a metallic retaining structure having flange portions extending outwardly therefrom at points spaced around the outside of the assembly, and a supporting structure for said electrode assembly having one end positioned against said header and portions at the other end joined to said flange portions.

13. An electric discharge device including a header having an outwardly extending metal flange, a unitary electrode assembly including a metallic retaining structure having flange portions extending outwardly therefrom at points spaced around the outside of the assembly, and a supporting structure for said electrode assembly having a flange resting on the flange of said header and portions at the other end joined to the flanges on said retaining structure.

14. An electric discharge device including a header having an outwardly extending flange, a

unitary electrode assembly including a metal retaining structure, a support for saidelectrode assembly including a flanged portion registering with the flange of said header and arm portions joined with said retaining structure, and a metal envelope for said device including a flange registering with the flange of said support, the flanges of said header, support,'and said envelope being bonded together.

15. An electric discharge device including a header having an outwardlyextending metal flange, a unitary electrode assembly including a metal retaining structure, a metal support for said electrode assembly including a flanged poran upwardly extending portion joined with sai 7 retaining structure, and a metal envelope for said device including a metal flange registering with the flange of said support, the flanges of said header, support, and said envelope being bonded together. V

, 7 WILLIAM s. BRIAN.

REFERENCES CITED Number Name Date tion registering with the flange of said header and 16 2,141,654.- Kott Dec. 27, 1938 

